Spinal pathologies and disorders such as degenerative, isthmic and iatrogenic spondylolisthesis, degenerative disc disease, disc hemiation, and stenosis may result from disease and degenerative conditions caused by injury, prior surgery and aging. These spinal disorders typically result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility. Kyphosis and lysthesis or anterior translation of one vertebra in relation to the next may occur in many of these conditions and pathologies.
Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Current surgical treatment of these spinal disorders includes decompression and restoration of the normal alignment of the spine with concomitant fusion. Techniques used to commonly achieve these goals may include laminectomy, discectomy, internal spinal fixation, correction of the kyphotic deformity and the insertion of implantable interbody prosthetics. As part of these surgical treatments, spinal constructs, such as, for example, bone fasteners, spinal rods and interbody devices can be used to correct the pre-existing kyphosis and vertebral translational deformity and to provide stability to a treated region. For example, during surgical treatment, interbody implants and spinal pedicle screws can be used to correct abnormal alignment of the spinal vertebrae and provide stability serving to immobilize the spinal motion segment, and with bone graft, can result in a stable fusion. This disclosure describes an improvement over these prior technologies.